textproduct: Quad Cities

KEY MESSAGES

- Another bout of fog is expected tonight into Monday morning; some fog could become dense and a Dense Fog Advisory has been issued for our southwestern areas

- A system will bring increasing chances (50-80%) of rain showers over the area Monday into Monday night

- A pattern change remains on track by mid-week, with much colder and brisk conditions for Wednesday through the end of the week; longer range signals show a wintry system may cross the region by weeks end

SHORT TERM /THROUGH MONDAY/

Issued at 220 PM CST Sun Nov 23 2025

Southerly flow will persist tonight in the wake of a passing high pressure system, currently located over central Illinois. The 23.12z HREF ensemble indicates increasing dew point temperatures from the southwest this evening into tonight, along with a stout low-level thermal inversion likely once again tonight. These factors should support another night of fog. This fog will likely become dense in spots, given HREF probabilities of a quarter mile visibility being around 50 to 70 percent in some locations tonight. With this level of confidence, we've decided to issue a preemptive Dense Fog Advisory for this evening through Monday morning for our southwestern half of the forecast area.

On Monday, a mid-level shortwave will approach the Corn Belt from the Four Corners region. Ahead of the system, we will see increasing clouds tonight, and eventually increasing chances (30-50%) of rain showers over the area (higher chances in the evening). What's interesting is that while Pwat values continue to be progged around 0.7 to 0.9 (up to an inch in some spots), the forecast QPF has gone down. This might be due to a lack of robust northward moisture transport as strong to severe convection is possible over the southern MS River Valley region, which could help sap higher moisture up here. A dProg/dt of the NBM exceedance probabilities of a quarter inch or more of total rain has steadily decreased over the last several runs, which are now only 20 to 50% over the CWA - highest over our southeast. Current forecast has total rainfall between 0.05" to the northeast to nearly two-tenths of an inch over over our northwest and southeast, which matches up well with the HREF PMM QPF through Monday night. Heavier rainfall amounts are not anticipated due to a lack of convective potential. With the cloud cover and rainfall expected, this should help tamper temperatures a bit, with forecast highs Monday in the lower 50s for most.

LONG TERM /MONDAY NIGHT THROUGH SUNDAY/

Issued at 220 PM CST Sun Nov 23 2025

Monday night into Tuesday: likely chances of rain showers (50-80% in the evening) will continue before gradually dissipating as the core of the mid-level shortwave moves through the area. There will be some residual rain possible Tuesday morning, but attention quickly turns to a potent cold front progged to sweep through the area Tuesday night. An attendant northern stream mid-level shortwave approaches the area from the Pacific NW, supporting a cyclonic flow/cold air advection (CAA) regime. This will spark a pattern change over the area, with much colder and brisk conditions in the wake of the fropa. The NBM suggests high temperatures going from the 50s on Tuesday to the middle to upper 30s on Wednesday, so it will feel noticeable cooler (just in time for busy Thanksgiving travel). The CAA will keep breezy conditions in place, with steep low-level lapse rates and enhanced momentum transport. The ECMWF EFI shows values of 0.7 to 0.9 for wind gusts on Wednesday, indicating an unusually breezy day, with gusts of 25 to 35 mph possible. Coupled with the cooler temperatures, it will feel pretty brisk. In terms of precipitation, we're not expecting much, if anything, to develop.

Thanksgiving into Saturday: it will continue to be on the chilly side, with low temperatures each morning in the upper teens to lower 20s. Coupled with the winds, wind chills will fall to the teens area- wide, and even some single digits are possible across our north. Friday night into Saturday could be active, with a wintry system expected to move into the region. There are some varying amounts of moisture available with this system, but it could be our first widespread snow-maker of the season. How much snow remains uncertain, but the NBM does have probabilities of 1 inch around 20- 50%. Not great news for snow lovers, but this suggests some measurable snow is possible with this system.

AVIATION /00Z TAFS THROUGH 00Z TUESDAY/

Issued at 522 PM CST Sun Nov 23 2025

Next 4 to 5 hours will bring VFR and light winds to the area before an IFR/LIFR ceiling moves into the area from the south. This will also lead to reduced vsbys. Some of these could be 1/4mi or less. However, confidence in occurrence at TAF sites remains low, so will continue the hedge with 1sm.

DVN WATCHES/WARNINGS/ADVISORIES

IA...Dense Fog Advisory from midnight tonight to 10 AM CST Monday for IAZ040-051-052-063>065-067-077-078-089. Dense Fog Advisory from 9 PM this evening to 10 AM CST Monday for IAZ076-087-088-098-099. IL...Dense Fog Advisory from midnight tonight to 10 AM CST Monday for ILZ024>026. Dense Fog Advisory from 9 PM this evening to 10 AM CST Monday for ILZ034-035. MO...Dense Fog Advisory from 9 PM this evening to 10 AM CST Monday for MOZ009-010.